clean off
To rid a surface of dirt, grime, or objects. A noun or pronoun can be used between "clean" and "off." Just clean off the desk and stack those books over here. Get me a sponge so I can clean this sticky table off.
clean something off
and clean something off somethingto take something off something; to remove something such as dirt or dirty dishes. Please clean the table off and put the dishes in the kitchen. I'll clean off the table. Judy cleaned the writing off the wall.